William Oh, M.D.
Colon & Rectal Surgery Physician · Irvine, CA
William Oh, M.D. is a colon & rectal surgery physician with a practice address in Irvine, California, and NPI 1598100323, issued on May 7, 2013. Check the license (California A136780, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- William Oh
- Credential
- M.D.
- Primary taxonomy
- Colon & Rectal Surgery Physician 208C00000X
- License number
- A136780 CA
Self-reported in NPPES; status is on the state search - Practice location
- 16405 Sand Canyon Ave Ste 280, Irvine, CA 92618
- Phone
- (949) 557-0370
- Enumerated
- May 7, 2013
- Record last updated
- May 7, 2026
- Fax
- (949) 557-0370
- Medicare enrollment
- Enrolled (PECOS I20190927001873); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest colon & rectal surgery physician records → All 198 in California → Look up another NPI →
Also registered at 16405 Sand Canyon Ave Ste 280
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Ziyad Jabaji, M.D.Colon & Rectal Surgery Physician1366760514
- Rashmi Kumar, MDGastroenterology Physician1396007068
- Patrick LeeTransplant Hepatology Physician1013476126
Verify William Oh in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A136780Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
42% fewer Medicare Part D claims than the average colon & rectal surgery physician in 2024
111 Medicare Part D claims for 45 beneficiaries, against an average of 192 among the 1,836 providers of this specialty who prescribed in Part D. 29 claims were for opioids.
Most prescribed
- Oxycodone Hcl19 claims
- Metronidazole15 claims
- Amoxicillin-Clavulanate Potass14 claims
- Neomycin Sulfate12 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Industry payments in 2024: $133.51
5 payments; by number, the most common kind was food and beverage; the largest payer was Intuitive Surgical, Inc. The 1,524 providers of this specialty with any payment received $3,468.16 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- Hoag ClinicNewport Beach, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
William Oh among 198 colon & rectal surgery physician records in California
William Oh, M.D. is one of 198 colon & rectal surgery physician records with a practice address in California. 87% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2013, is newer than 79% of them.
- NPI issued2013 · 79% of these records are older, 15% newer
- In a Medicare fileYes · 87% of these records are
- In the CMS Doctors and Clinicians fileYes · 75% of these records are
- Graduated2013 · median 2002 among the 149 with a school on file
- Record last updated2026 · 54% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 208C00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Colon & Rectal Surgery Physician providers in California
There are 198 colon & rectal surgery physician records in California.
All 198 in California → Every provider in Irvine → Colon & Rectal Surgery Physician nationwide →
The 8 colon & rectal surgery physician records with the nearest ZIP codes
- Elizabeth Arcila, M.D.Irvine, CA 926181093056780
- Carlos Esparza MonzaviIrvine, CA 926181750762001
- Ziyad Jabaji, M.D.Irvine, CA 926181366760514
- Siamak Milanchi, M.D.Irvine, CA 926181083829956
- Matthew Sherman, M.D.Irvine, CA 926181942216940
- Sonny Wang, M.D.Irvine, CA 926181811187560
- Theodore Coutsoftides, MDHuntington Beach, CA 926491144411414
- Robert Belt, MDLaguna Beach, CA 926511023223849
Common questions
What is William Oh, M.D.'s NPI number?
William Oh, M.D.'s National Provider Identifier (NPI) is 1598100323, issued on May 7, 2013. An NPI identifies a provider in billing; it is not a license.
Where is William Oh, M.D. located?
The NPPES record lists a practice address at 16405 Sand Canyon Ave Ste 280, Irvine, CA, 92618. Phone: (949) 557-0370. Providers update this record themselves, so call before visiting.
How can I verify William Oh, M.D.'s license?
NPPES lists California license number A136780, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does William Oh, M.D. prescribe under Medicare Part D?
In 2024, William Oh, M.D. had 111 Medicare Part D claims for 45 beneficiaries; the average among colon & rectal surgery physician prescribers was 192. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.